These visualization use baby names from Social Security Card applications from 2010 to 2020 to create the respective visualizations.
The data used is from Data.gov.
The line chart basically shows the number of babies per year that have matching Nintendo character names.
The heat map shows the popularity/ranking of each name in regards to every other name that was used to apply for a social security card that year.
It could be a coincidence, but it seems like the number of babies that share names with Nintendo characters increases when Nintendo releases a new game during that select year.